Elevator accident ratesgreenspun.com : LUSENET : Elevator Problem Discussion : One Thread
During a recent bullshitting session we were discussing the best way to minimize injury if you were caught in an elevator in free fall. (There's nothing like arguing about something that all parties are completely ignorant!) Some interesting ideas and questions came up and maybe someone with actual industry experience could answer them.
I was guessing that most elevator accidents involve getting things caught in the doors and that these sorts of accidents are infrequently fatal. I was also guessing that accidents involving falling down the hoistway were the most frequent source of fatalities. Finally, I theorized that actual free-fall of the car was quite rare. How'd I do?
Considering free-fall only, which kind of elevator is safer: a hydraulic or a cable elevator? Assuming simple lack of maintenance (and not, for example, airplanes slicing through cables), what needs to fail to cause a cable elevator to make an uncontrolled descent? What about a hyraulic? (I was reading the notes and I see that catastrophic loss of piston integrity, like the bottom falling off of it, can cause a hydraulic elevator to drop)
Thanks for your time.
-- Joe Marshall (email@example.com), December 01, 2003
why worry......it is so rare that noone gives a rats about socalled freefalling...you have been watching too many movies and having a too much to drink...go away and annoy someone else with your pathetic questions
-- dayle (firstname.lastname@example.org), December 02, 2003.
But Dayle, I'd rather annoy *you* with my pathetic questions.
Why did you even bother responding? You certainly gave no useful information. I already knew that Australia has its share of wankers, and you have amply demonstrated your knowledge of grammar and spelling in your other posts.
Next time you are tempted to reply to an admittedly naive question, pause for a moment and engage your brain. Ask yourself if you are contributing to the conversation. If not, then simple silence is your best response. The moderator of the group is the person with the responsibility to filter out irrelevant posts.
-- Joe Marshall (email@example.com), December 02, 2003.
Hi Joe I liked your question, first off I would like to know what country you are in for code referance. Dont your elevators all have airbags yet?, hae you seen the recent american elevator movie THE SHAFT or how about the old movie THE LIFT made in europe. Jim
-- Jim (firstname.lastname@example.org), December 02, 2003.
hey id like to know where the spelling mistakes are...and while I,m at it you know NOTHING about elevators...I,d be a bit more considerate if I was U.
-- dayle (email@example.com), December 03, 2003.
I'm in Boston, Massachusetts. We're a little more socially conservative than California, so our elevators don't have air bags, anti-lock brakes, or emissions standards, but the way things are going....
I may have seen `The Shaft'. I vaguely remember seeing some movie about a `killer elevator', but all I remember is that it wasn't very good. I did more than my share of `elevator surfing' in college, so I could spot some of the obvious errors. Besides, how scary can something be if you can simply walk away from it?
-- Joe Marshall (firstname.lastname@example.org), December 03, 2003.
Hi Joe Good One Joe, It might not be so funny in a few years, we might have that stuff someday. Arnold might put that off for a while.
Did you here that the california budget is in the red so much he want to cut and combine government departments. He wants to combine the Califonia Highway Patrol and the Department of Fish and Game. The new official name will be the Department of Fish and Chips.
-- Jim (email@example.com), December 04, 2003.
This is not the dayle I know from old, the stress at the Big "O" in Aus must be taking it's toll. I did warn you dayle, going from the time scale you have not peaked yet, F**K them and leave you will be a better and happier engineer Ps Happy Xmas mole.......
-- mole (firstname.lastname@example.org), December 06, 2003.
no not too much stressing.....just to much alcohol on the night....I apologise to you all....alcohol and internet dont mix sometimes
-- dayle (email@example.com), December 06, 2003.
You did really well in guessing that free falling is very rare. I have personally never heard of such an accident (in ontario, anyway) LOTS of things have to fail in a traction elevator to cause it to "free fall." Even if you stood on top of an elevator car and sawed through the ropes, the safeties (type "A") would activate and prevent the car from dropping more than about 1 1/2" at the most. in a higher speed machine (more than 150' per minute) they use type "B" safeties which work more gradually to slow and stop the car. In either case, if EVERYTHING failed, the best thing to do is to lie down, spreading out the force on your body. As for which is safer, I vote for Traction elevators. Hydraulic elevators do not require safeties. and BTW- falling up in an elevator is more dangerous and likely than falling down!
-- Bill (Willys42@rogers.com), March 04, 2004.
Yup free fall is pretty rare condition, there's quite a bit that needs to go wrong for a traction elevator to free fall, I guess the most common would more likely to be failiure of the sheave bolts or worn teeth on the crown/worm rather than suspension failiure. a drive failiure would usually result in the elevator moving up the shaft (empty car) rather than free falling as the counterweight is generally 50% heavier than the car.
Indirect acting (suspended via wire ropes) hydraulic passenger elevators in the UK are fitted with safety gears, Direct acting (car bolted directly to the piston) hydraulics are generally fitted with a rupture valve which should stop the car if the pipe bursts, during testing i've found a fair amont of these that have been so far out of adjustment that they would never have worked. Pipe bursts are also fairly rare, I can't recall any infact that have not be as a direct result of pressure testing even then it's usually the connections that fail not the hose itself.
-- Phil Hewer (firstname.lastname@example.org), May 30, 2004.
i think free-falling elevator accidents are most likely underreported, and i know so from experience. I was involved in one a few months ago, where the elevator free-fell from the 9th story and it was never let out in to the public media. and i dont think there is any correct and safe way of falling to minimize injuries that you could possibly remember or act on when an elevator begins to fall without you expecting it.
-- B (email@example.com), July 10, 2004.
Free falls are extremely rare. With all due respect, I'd like full details on the one you experienced. I don't question your sincerity in thinking that is what happened. However, if you were on an elevator that truly free fell nine floors, I doubt you'd be posting on this board.
-- John Brannon (firstname.lastname@example.org), July 11, 2004.
The elevator fell from the 9th story and jolted to a stop in between the 5th and 6th floor...the doors opened up and then slammed shut and fell again to the 1st floor. And I'm definately fully aware that I wouldnt be here if it didnt stop briefly.
-- B (email@example.com), July 24, 2004.
Mia 6, if an elevator truly fell, the only things to stop it are the safety device and the pit structures.
If the safety device arrested the fall, that's it. It will stay there until the safety device is manually released. If it hits the pit structures, that's as far as it can go and if it free fell to that point, from nine floors, or five, it will hit HARD.
What happened after you got off at the first floor? Did someone have to come and fix the elevator, or did it continue in service?
It sounds as if the elevator ran "out of control" from nine to five, paused and continued to one.It may have been running erratically and perhaps even oversped a bit, but it did not fall in the usual sense of the word.
Tell me where I'm wrong - I may still misunderstand what you are saying. Be open to the possibility that your perception is innacurate.
-- John Brannon (firstname.lastname@example.org), July 25, 2004.
please refer to my previous answer
-- dayle (email@example.com), July 26, 2004.
What are the stat regarding elevators that shot up, such as the recent accident in times square. My understanding is that those new elevators have no counterweight system.
-- Simone (firstname.lastname@example.org), October 08, 2004.
Relating to all the previous stories free fall is extremely rare and requires gear unit failure as stated, lift installs and refurbs now include bi-directional safety gears that are operated by the overspeed governer, the description of falling from floor 9 then stopping and restarting wouldnt be possible, the overspeed facility trips the safety circuit electricaly at a lower before the safety gear becomes engaged, this requires a manual reset. sounds more like tipped a lock then gone into reset. Lift breakdowns are far more common on newer installations due to the more complex safety circuits and although this is inconvenient to passengers they should feel safer,
-- Andy Naylor (email@example.com), October 16, 2004.
As far as I know which is reading it in Ripley's believe it or not or similar book there has never actually been a fatality from a free fall elevator accident.
Wires must break (all of them) arrestor shoes on side of life must fail and finally the hydraulic rams at the bottom which can absorb a lot of the free fall speed must fail.
I know a lift fell from a very high floor on the empire state building many many years ago but even then the sole passenger survived because of the rams. She was critically injured though.
-- Tim Nunan (firstname.lastname@example.org), October 20, 2004.
I heard that the woman that fell in the empire state building because of an airplane motor cutting the cables, survived because the wires piled up in the pit and acted as a giant spring when the elevator hit. The largest danger of free falling is falling up in a traction elevator. Most traction elevators have a governor sytem with safeties that stop the car from falling down.The code has only recently required a rope brake to stop a car free wheeling in the up direction. Since the counterweight is equal to the car plus 45% of the full load capacity, often times when riding the counterweight is heavier.This is rare but it does happen. My guess would be due to a failure of the electric brake that normally holds the elevator at floor level upon stopping.
-- Lonnie Snow (email@example.com), October 22, 2004.
This is from an article in the San Diego Union Tribune and happened on October 23rd, 2004.
TIJUANA, Mexico – Two five-year-old children fell to their deaths Friday in an apparently malfunctioning elevator at Tijuana's Grand Hotel, state authorities said.
The mother of one of the children, Alicia Barajas, 46, was hospitalized in stable condition with shock and broken bones, after she and family friend Linda Rubio entered an elevator shaft whose car appears to have been detained at a higher floor.
The woman and girl fell almost 50 feet (15 meters) to the bottom of the shaft; the girl died instantly.
Barajas' son, Jonathan Cardenas, somehow managed to hold onto the ledge of the door opening, but was crushed and practically decapitated when the elevator car finally descended to the lobby level.
Authorities are still investigating the accident at the luxury hotel and have not yet filed any charges in the case, said Maria Teresa Valdez, assistant attorney general of Baja California state.
"This was an unfortunate accident caused by a technical problem that was not repaired quickly enough," Valdez told reporters. "At this time, we cannot say who was responsible."
Valdez said the hotel management – which refused to comment to reporters on the case – had apparently hired an independent contractor to maintain the inspect the elevator.
The hotel is located adjacent to Tijuana's Plaza Agua Caliente mall.
Juan Gil, a doctor who runs a Spa and Oxygen Treatment Center at the Plaza Agua Caliente, said he saw the commotion at the elevators across from his clinic and went out to help.
"I put on robe and went to see if I could help," Gil said. "Police told me there wasn't much I could do for the children. It took so long for them to be rescued. It's really a tragedy."
End of Story *********************************************************** I've heard on local Tijuana radio and tv reports that the little boy was actually totally decapitated from the weight of the elevator.
This is a very sad and unfortunate story.
-- Layla (firstname.lastname@example.org), October 25, 2004.
As illustrated by the last answer there are more deaths due to failure of the lift doors than cars falling down - or up lift shafts. There was a case in the UK a few years ago where two people fighting fell against the landing doors which then opened and they both fell to their deaths down the shaft. Following this the HSE issued an instruction for building managers to test the lift doors on buildings they were responsible for by pushing them - not sure what would happen if they failed & opened !
-- John Murrell (email@example.com), November 24, 2004.
To return to the original opening line about being in a falling lift/elevator, there is no way of minimising your injuries, sure you hear the tale of jumping just before it crashes to a stop but you would only be moving UP in comparison to the lift, in real terms you would still be travelling DOWN,and besides, how would you know when the lift is going to crash so that you could leap before it did?
You could stand with knees, hips and ankles slightly bent rather like a parchutist so that your body acts as a shock absorber, but if it is a fast fall I personally don,t give you much of a chance. Dont worry about it, you are far more likely to get run over by a truck than be killed in a falling lift
-- geoff judge (firstname.lastname@example.org), November 24, 2004.
Probably more of an issue of worn out gibs and or door hangers rather than the doors opening up. my guess it was more like a doggy door opening and letting them fall. A case in point to show the need for proper elevator maintenance.
-- John (email@example.com), November 24, 2004.
From memory, the accident with the 2 people fighting was in Southampton and the doors DID swing open from the hanger rollers (just like a big catflap) the shoes of the doors were almost non- existent. Saw something similar in a multi-storey car park where the lifts had aluminium tracks which just corroded away ,probably due to the number of vagrants pissing against the doors, and the rocksalt used to grit the top floor during snow and ice. Fortunatly there was no accident but the service guy found that if he pushed the top floor door towards the shaft the track moved into the shaft and fell off. The aluminium was replaced with phopher-bronze, and plenty of pitch and bathroom sealent, to stop any further water ingress.
-- geoff judge (firstname.lastname@example.org), November 26, 2004.
Otis Waygood invented the first safety feature in lifts - quite simple really - basically the cable was attached to leaf spring and the weight of the lift made it bow in the middle. If the cable broke to spring reverted back to shape and the ends jammed in the shaft stopping the lift from falling. The invention made it possible to install lifts in high rise buildings. There are other dangers however. There was a case about 3 years back in South Africa where a man rushed to catch a lift and his legs got caught in the doors (he must have fallen). the lift is supposed to stop when this happens but in this case it continued up, amputating both legs....
-- Chris Rose (email@example.com), December 02, 2004.
I found this web site at answering questions of elevator/escalator saftey and accident causes to be very helfull.
I have worked in the elevator industry for over 25 yrs as a technician/troubleshooter/adjustor and Local Representitive. I have been involved in many accident investigations but never a death investigation.
-- Flying Phil (firstname.lastname@example.org), January 22, 2005.
I am conducting research on elevator accidents for my own edification. I was crushed in between elevator doors 5 years ago when the sensors failed to work. I was physically pulled into the elevator by several passengers resulting in permanent injury. I thank God that someone was inside the elevator as it was apparent that the doors where going to continue to close and then possibly descend to the 1st floor. Has anyone else heard of such a thing?
-- Tresa (email@example.com), January 30, 2005.
Please be assured that no elevator, or lift, could not have moved if you were still in the way of the doors due to the electrical locking system on each door. In simple terms, the door motor would have had some form of stall protection, either a current monitor, which, when it reads the higher than normal current, would have reversed the doors, or a timer that counted the seconds from when the door started until it stopped under normal conditions.Once this timer tripped it would have reversed the doors. For example if the door normally takes 4 seconds, the timer would be set at a max of 10 seconds but more usually 7 secs. and it is not unusual for both to be fitted ,depending on type of doors, age of lift, etc.etc. Sounds to me like a claim here, but are you sure you weren't injured by those in the lift pulling you in?? You have not specified the injury, but the door max pressure is predetermind, if the doors need a 1 amp motor to move them, that is all they get.
-- geoff judge (firstname.lastname@example.org), February 01, 2005.